Aiming at an improvement of working efficiency, some of working machines, such as hydraulic excavators, are equipped with work supporting devices in a cab or an operating room for remote control. In particular, due to facilitation in three-dimensional position measurement using the GPS, it has recently been proposed to measure the three-dimensional position of a working machine and to display the measured position together with, e.g., a target position of work.
One example of such a support device is disclosed in JP,A 08-506870. In a self-propelled landform modifying machine, such as a truck-type tractor or a ground leveling machine, the disclosed support device is used to display a desired site landform (target landform) and an actual site landform (current site landform) in superimposed relation, to determine a target amount of work from the difference between the desired site landform and the actual site landform, and to control the machine. In addition, the disclosed support device graphically displays the difference between the desired site landform and the actual site landform in a plan view.
Also, JP,A 8-134958 discloses a remote-controlled work supporting image system in which data of landform under working and design data as a target value are displayed in superimposed relation on an operating display installed in an operating room.
Further, JP,A 2001-98585 discloses an excavation guidance system for a construction machine having an operating mechanism for excavation, which is operated to carry out the excavation for modifying a three-dimensional landform into a target three-dimensional landform. In the disclosed excavation guidance system, a position where a plane passing a current three-dimensional position of a bucket crosses the target three-dimensional landform and the bucket position are displayed on the same screen.